Monday, May 31, 2010

Anti-Aging 101: Anti-Oxidants

As part of my Anti-Aging 101 Series, I have decided to revamp old posts that describe different ingredient categories. I'll go over how and if these ingredients work. Not a lot has changed regarding some of these ingredients (such as anti-oxidants), but I'm planning to take advantage of the 2 cosmetic dermatology books I have in revamping these posts, so there likely will be some new info.

The involvement of free radicals in the aging process was first proposed all the way back in 1956, and it is one of the few things in anti-aging that is widely accepted. Free radicals have not only been implicated in the overall aging process, but also in photoaging, skin cancer and inflammation (which in turn contributes to aging, photoaging and some postulate skin cancer).

So, what is a free radical? How can you mitigate all this damage, and what exactly is an anti-oxidant?

Well, what exactly is an antioxidant? It's something that fights free radicals. I think that it was explained best by Alton Brown from the Food Network.

Basically, the free radicals are created when they give up or lose an electron. That lose leaves a hole, and the newly created free radical doesn't know how to cope with this. It goes crazy trying to fix that hole, which means in your skin the free radical bounces around in skin cells, causing damage to things like your cell membrane or even your DNA, attempting to fix that hole.

What do the free radicals do to your skin? The reactive oxygen will go around seeking another electron, and it doesn't particularly care where it comes from. It can attack cellular proteins, cell membranes, parts of the cytoskeleton, the extra-cellular matrix, even the DNA of the cell itself. We don't know all of the exact mechanisms involved in free radical damage.

So, now that you know what a free radical is, how are they created? Pretty much anything that challenges the skin.
•UV Rays (Sunlight)
•Drugs
•Pollution
•Heat
•Cold

Antioxidants help to control the free radical damage by getting rid of the free radicals. They can donate an extra electron to the free radical, filling that hole and fixing the behavior. The free radical no longer goes around causing damage.

The skin does have it's own antioxidant system to help to counteract these free radicals, however over time the free radicals can continue to damage cells and their DNA. In addition, your body's antioxidants decrease with age, leaving the free radicals unchecked, and leaving your cells, cell membranes and DNA more vulnerable to damage. This results in loss of firmness, radiance, elasticity and can contribute over time to aging of the skin. Notice that I said over time. Because in theory you're experiencing this type of damage all the time, though more so after exposures to sun and such. But, the damage is cumulative and although you won't be able to see results right away, chances are you will see them in the long term. I think of this as similar to wearing sunscreen. You might not see a big difference now, but if you compare yourself to your friends that didn't do it in 10 years, you'll likely see a difference.

The skin does have it's own anti-oxidant system to help to counteract these free radicals. Our bodies are smart and produce anti-oxidants as part of its own normal processes as well as in response to those same stresses that create the free radicals! So, expose yourself to UV rays, there will be free radicals produced, but your body will respond with anti-oxidant production. Sounds great, right? Sure, except that it takes your body quite a bit longer to produce the extra anti-oxidants than it took the sun to create the free radicals. So, you will have a lag, which allows time for that damage to take place. As well, your body's ability to produce those anti-oxidants will decrease with age. That means more time for that damage to occur.

How does all of this translate over to your skin? You'll see loss of firmness, radiance, elasticity and can contribute over time to aging of the skin. Notice that I said over time. Because in theory you're experiencing this type of damage all the time, though more so after exposures to sun and such. But, the damage is cumulative and although you won't be able to see results right away, chances are you will see them in the long term. I think of this as similar to wearing sunscreen. You might not see a big difference now, but if you compare yourself to your friends that didn't do it in 10 years, you'll likely see a difference.

A huge number of antioxidants are on the market right now, here's a quick overview of a few of them. Note that some of these are applied topically, but some can also be taken orally. Is one better than the other? We're not sure. But, since most of these are simply vitamins, I think you probably couldn't go wrong with improving your diet and using a product with an anti-oxidant in it. Currently Vitamin C is the only anti-oxidant that really "treats" aging once it has occurred. This is likely due to the collagen production boosting affects of Vitamin C rather than the anti-oxidant effects. So, anti-oxidants are aging preventors, with the exception of Vitamin C. Just keep that in mind.

Now, this is the boring part of the post where I list a bunch of ingredients and quote a little bit of stuff from some reviews I've found on-line and then researched a bit on my own to make sure stuff was accurate. I'm by no means an expert on anti-oxidants (especially since there are so many of them), but here's some info on the ones you're most likely to run in to.

Allantoin
Long used to help protect the skin in creams and lotion, allantoin was thought to be a skin protectant. It has been called a "cell proliferant, epithelization stimulant, and a chemical debrider." Basically, it helps to exfoliate and stimulate new skin growth.

Alpha Lipoic Acid (ALA)
ALA is unique, as it is soluble in both water and lipids, so it easily penetrates into the skin. It seems to help protects Vitamins E and C, helping to boost their activity within the cell by "reenergizing" them. It is also converted in the skin into another chemical that has it's own antioxidant properties.

Copper Peptides
Copper has long been known to be important in the creation of collagen and elastin (again, important parts of the dermis), both of which are decreased with aging. Copper does have a bit more research than many other topical antioxidants, and some well design (aka- double-blind placebo controlled) research studies have shown improvement in fine wrinkles, hyperpigmentation and decreased photodamage. Copper increases the body's superoxide dismutase levels (see below). They even found a 17.8% improvement in skin thickness! Overall that does sound great, and copper is very appealing to add to products since it is non-irritating and pretty cheap to add to creams.

Dimethylaminoethanol (DMAE)
When used topically, DMAE has been found to increase firmness of the skin, likely because it helps to reduce some linking between proteins in the skin that happens with aging, as well as separate antioxidant properties.

Glutathione
Composed of glutamic acid, cysteine, and glycine, this little protein is found in all animal tissues, is one of your body's main antioxidants and is very decreased in the skin after skin exposure. Unfortunately it is water soluble, which means it does not absorb well when taken orally or applied topically. Not available in cosmetic products.

Grape and Grape Seed Extract
Proanthocyanidin, a very powerful antioxidant is found in grapes and grape seed extracts. While this antioxidant doesn't have strong evidence that it works topically (really, most of these things I'm listing don't have much evidence anyways), it was found to have strong effects on free radical damage of fat cells especially, as well as improved wound healing and prevention of tumors (both in mice).

Green and White Tea
Green Tea has some great things in it called polyphenols and they are one of the most widely studied anti-oxidants on earth. Polyphenols are a very large and diverse family. There are literally thousands of them, and they are all found in two. The 4 major ones found in tea have long complicated names, but they are shortened to ECG, GCG, EGCG and EGC. Confused yet? The EGCG is the main polyphenol that is responsible for anti-oxidant activity in both green and white tea and it is the most potent. It is important to know which polyphenols are included in a formulation, and to what concentration. The most effective products will contain 50 to 90% polyphenols and will be brown.

EGCG does offer photoprotection. This has been seen in mice with both oral and topical application, as well as in human skin. It is dose dependent (meaning, more ECGC will result in more effects), resulting in a decrease in redness, sunburned cells and less DNA damage after UV exposure.

Note that most of these studies were done specifically with ECGC as the ingredient. There are thousands of polyphenols in green tea, and most products on the market that contain green or white tea are not of a high enough concentration to demonstrate that they work. Look for ECGC ((-)EpiGalloCatechin-3-O-Gallate) and concentrations over 50%.

Idebenone
This is the synthetic analog of Ubiquinone (Coenzyme Q 10). It weighs less than CoQ10, and therefore has been shown to penetrate the skin more effectively. It has higher anti-oxidant activity than CoQ10, Vitamin E, Kinetic, and Vitamin C in a lot of studies. Currently it is available in Elizabeth Arden's Prevage Line only.

Lycopene
A natural pigment that is responsible for the red pigment we see in tomatoes, pink grapefruit, watermelon and apricots. Due to the chemical composition of Lycopene (something about double bonds) it is a stronger anti-oxidant than beta-carotene or Vitamin E. Increased intake of lycopene has been shown to prevent cancer and cardiovascular disease. Currently there is little information available regarding its use in anti-aging skin care products.

Melatonin
Yup, that stuff you take to help prevent jet lag is an antioxidant! It's released by the brain, and it's able to both act as an antioxidant, increase the activity of other antioxidants and to help decrease redness from sunburn. Oh, and help you reset your internal clock, but I'm not going to go into that!

Panthenol
An alcohol derivative of Vitamin B5, Panthenol is actually a humectant (see, it's here in my moisturizer post), and is very easily found in moisturizer, shampoo, conditioner, etc. Once it's in the skin, it get converted to an acid that is an important cofactor for Coenzyme A, allowing your skin to function normallly. It's pretty stable, but doesn't do well in acidic or basic environments or high heat.

Soy Isoflavones
Only available orally, Genistein and Daidzein help to enhance the antioxidants your body already makes. Mice were fed a solution with these 2 isoflavins, and for weeks afterwards their skin had decreased roughness and improved collagen levels after sun exposure. Does this mean that if you eat soy it will make your skin smoother? Not quickly, but it may help in the long run.

Spin traps
Spin traps are kinda cool, they react with the free radicals to create unreactive free radicals, so they can't cause any damage! I love the Your Best Face products, which feature Spin Traps.

Superoxide Dismutase (SOD)
An enzyme that destroy a very active reactive oxygen species (super oxide), this is a very big enzyme and it has a really hard time penetrating into your skin. This makes it very difficult to use as a topical agent. If it could get there, it would be very useful and would dramatically decrease redness from sunburn as well as the damage from the UV exposure.

Ubiquinone (Coenzyme Q 10)
This one likely sounds very familiar, as it can be found in a huge number of products on the market right now. It's also found in foods like fish and shellfish. CoQ10 is fat soluble and works within the cell's mitochondria (a little energy creating organ found within each cell) to help create energy and it helps to reduce damage of certain proteins even better than vitamin E. CoQ10 levels have been found to decrease with age, one reason that many feel it could be particularly useful for aging skin. It has been found to easily penetrate the skin when applied topically and then to significantly decrease an enzyme that chews up collagen after UVA exposure. Supplementation with CoQ10 has been found to reduce crow's feet, and supplementation will increase levels in the epidermis.

Vitamin A
Vitamin A was the first antioxidant to be used for anti-aging, and it's synthetic derivatives (the retinoids) are even more useful given their stability. Retinoids are the only agents that have been found to be effective against wrinkles in studies and are the gold standard.

Vitamin C
Also known as L-ascorbic acid, Vitamin C is that thing that gives you scurvy if you're deficient. It's water soluble and works in the early stages of production for collagen (it even helps to stimulate collagen production) and a few amino acids. Vitamin C has been found to be low in the skin after sun exposure and applying it topically after sun exposure will specifically combat the ROS brought on by UV exposure. Very few studies on Vitamin C in the setting of photodamage or in humans (rather than in petri dishes) have actually been completed.

Vitamin C is a great candidate for use. Unfortunately, no studies have found increased levels in the skin after oral supplementation, hence so many topical forms on the market. It can be formulated as water soluble or lipid soluble. Unfortunately, most of them can not penetrate the statum corneum (the very outer layer of the epidermis), which makes them expensive products that don't work. You will want a product that is lipid soluble, and that the company claims is "nonionic" or more lipophilic, both of which will help penetrate the skin. If they have some evidence of penetration that would be even better.

Vitamin C is easily degraded by both heat and light, as well as exposure to air. That means most products are inactivated within hours of opening them, therefore all of your money has just been wasted. Only buy Vitamin C preparations that are in air-tight packaging (such as a pump) that protect the product from any UV exposure.

Vitamin E
Alpha-tocopherol is found in membranes and tissues galore, and in fact the term "Vitamin E" actually refers to 8 different molecules that have the same activities (the one labelled "alpha-tocopherol" is the most active form). It is lipophilic, meaning it likes being around fats and cell membranes. It has been found to be the primary lipid-soluble anti-oxidant in the skin, and subsequently has become a very popular choice to help treat skin issues of all sorts. Higher vitamin E levels have been linked to lower risk of infection and cancer in elderly patients that have high blood levels of Vitamin E. Topical and oral Vitamin E has been shown to decrease sunburn damage (swelling, redness and inflammation) and even wrinkling when applied prior to UVB exposure.

So, should you take Vitamin E and apply it to your skin before going out in the sun? Hard to say. Studies have found that by taking a Vitamin E supplement every day you did not have any meaningful photoprotection. Currently many dermatologists feel that it likely needs to be used with other anti-oxidants such as Vitamin C to have an effect. As well, you can have reactions to certain types of Vitamin E (Tocopherol acetate seems to be the worst).

There are important things to remember about antioxidant use to fight aging. 1. It has not been proved clinically, even though it seems logical that antioxidants would help fight signs of aging.2. Any effects you will see are likely to occur over a long period of time.3. If you're going to use antioxidants on the skin, the formulation must be stable (meaning the antioxidant doesn't break down and become useless), must be a high enough concentration and must not only get to the target area but must stay there long enough to work.

I've received samples in the past of some of the products mentioned in this post.

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